Today's writers and authors have to learn how to wear many hats in order to get their words in front of readers, but in my view, the worst is editing. I hate editing. I really do. Michael says I've got a good eye for it, and maybe that's so for certain aspects of it, but I hate doing it and so I'm unlikely to make up for my shortcomings any time soon. This causes me to like and admire the editors I've come to know. The way I see it, anyone who can repeatedly, voluntarily immerse themselves in crappy writing for the sole purpose of making it better/coherent/readable is a bona fide hero.
With that in mind, I'd like to recommend to you this article via Lithub, one of my very favorite ways to keep my pulse on what's going on in the world of words. In this essay, Ben Dreyer (self-styled "Copy Editor of the Internet") airs out over a dozen of the worst habits he finds in manuscripts, and every writer I've ever worked with (self included) has at least one of these, if not more. They're presented with wry wit, and if you don't burst out laughing after you've read his nightmare sentence, I'm likely to question your legitimacy as a writer.
Give it a read and see if Mr. Dreyer found yours -- and if you come back to drop them in the comments, I'll share mine, too.